Flexible rotary agitator for hoppers with variable eccentric mountings and spaced weights



July 17, 1951 FLEXIBLE ROTARY AGITATOR FOR HOPPERS WITH VARIABLE ECCENTRIC MOUNTINGS AND SPACED WEIGHTS I nvenl'Ors L. vo- Holzerzleihezz,

Patented July 17, 1951 UNITED STATES PATENT OFFICE FLEXIBLE ROTARY AGITATOR FOR HOP- PERS WITH VARIABLE ECCENTRIC MOUNTINGS AND SPACED WEIGHTS land Application March 22, 1946, Serial No. 656,491

9 Claims. 1

This invention relates to improved means for effecting the removal of material from bunkers, hoppers, bins and like containers, and more particularly to means for effecting removal of material in a relatively finely divided state, especially where the moisture content of such material may be relatively high. The invention has particular application to means for effecting the removal of finely divided coal from storage bunkers, hoppers, bins and the like, but as will be apparent to those skilled in the art the invention can be applied to many other comparable uses.

In bunkers, hoppers, bins and the like for the storage of such materials as coal, and which will hereinafter be generically referred to as bunkers, it is usual for the outlet therefrom to be of smaller area than the main cross sectional area of the bunker. With such constructions difficulty is frequently experienced in causing the material to flow through the outlet, particularly where the material is in a finely divided state, and especially if the moisture content of the material may be relatively high. Under such conditions operation may result in the formation of a tunnel through the material that starts at the outlet and extends upwardly through the mass. Such a tunnel is usually referred to as a rat hole, and once a rat hole is formed little material will thereafter flow out of the bunker.

Various means have heretofore been proposed to eliminate the condition above referred to, such means including the use of electromagnetic vibrating devices adjacent the outlet of the bunker for vibrating the side walls thereof and the use of solid probing rods, or hollow probing rods through which a blast of compressed air may be delivered, which are manually operated for freein the material.

It is an object of this invention to provide improved means for freeing the material in a bunker under the conditions above referred to that provides wide flexibility of application and use.

Another object of this invention is to provide a device of the type referred to which may be readily adapted to the configuration of a wide variety of bunkers.

Another object of this invention is to provide a device of the type referred to which by operation at different speeds can be used to meet the exigencies of a wide variety of situations.

Another object of this invention is to provide a device of the type referred to which is so constructed that injury will not occur if overload conditions are encountered.

Another object of this invention is to provide a device of the type referred to which is simple in construction, easily repaired, readily adjustable and highly efficient in use.

Other objects will appear as the description of the invention proceeds.

The present invention, which may be applied to any type of bunker, hopper, bin or the like, includes a rotatable chain, cable, rope or similar means suspended from the top of the bunker and herein referred to generically as a freely hanging flexible element which extends into the void in the coal or other material afforded by the rat hole, and which may be so constructed and operated as to meet the varyin requirements of different bunkers, different materials, different conditions encountered, etc.

The invention is capable of receiving a. variety of mechanical expressions only two of which have been illustrated diagrammatically on the accompanying drawings, but it is to be expressly understood that the drawings are for purposes of illustration only and are intended merely to exemplify some of the many possible expressions of the invention, reference being had to the appended claims for a definition of the invention.

Referring in detail to the accompanying drawings wherein the same reference characters are used in the different figures to designate corresponding parts,

Fig. l is a diagrammatic sectional elevation of a bunker provided with one embodiment of the present invention;

Fig. 2 is a diagram to illustrate the operation of an embodiment of the invention using a weight at the end of the suspended rotatable flexible element;

Fig. 3 is a comparable diagram to illustrate another mode of operation;

Fig. 4 is a partial diagrammatic elevation to illustrate an alternative way of providing a Weight on the suspended rotatable flexible element; and

Fig. 5 is an enlarged detail of one form of coupling.

Referring first to Fig. l, a bunker of any suitable size, configuration and construction is diagrammatically indicated as having an upper portion I0 from which extends a lower converging portion ll terminating in an outlet I2 through which the material, such as coal, must flow. In conformity with the present invention any suitable drivin means, such as an electric motor I3, preferably a variable speed motor, is mounted at or adjacent to the top or inlet portion of the bunker in such a way that its shaft It lies approximately along the vertical axis of the bunker outlet I2. Any appropriate means (not shown)v known to the art mayjbe used for varying the. speed of said driving means. I

Suitably suspended from said shaft I4 through a suitable driving connection I5 is a flexible?! member I6 in the form of a freely hangingchain that preferably extends approximately the 'full height of the bunker, i. e., intotheineighborhood 10 of the outlet I2. Connection I5 may'beof' any suitable construction but is preferably-such that if an excessive load is imposed on the element !5 said motor may rotate relatively to, and independently of said element. A preferred con struction is an overload clutch of any suitable construction such that the clutchmainta'ins its. driving relationship with the element I ,fo r all. mechanical loads below a certain liimting value, but when theload exceeds this value, the clutch will slip or disengage to prevent overloading of the motor I 3. Element I6 is connected to the output member II of said overload'clutch in any suitable way, and maybe swivelled thereto or merely hung therefrom. Under some conditions it is desirable that the element I6 be so mounted that it may be shifted laterally with respect to theshaft I4, as for example by pro viding a slidable connection between the upper end of the element I6 and the output member I1 of the clutchas diagrammatically indicated at 22 in Figs. 4 and 5; and it may be desirable to make the entire unit including themotorycou pling, etc., slidable transversely of the axis of the bunker in one or "more directions, as by mounting the unit on an'adjustable base i'ndii cated in dotted lines at 22 in Fig. 1;' so that by adjustment the element It may have different degrees of eccentricity with respect to the driving shaft- I 4 and/or different positioning with 40 respect to the axis of the bunker.

Element I5 may be unweighted, but preferably it is terminated at its lower end by any'suitable weight I9 which may be a mass attached to the end of the element as indicated'in Fig. 1 or, alternatively, the weight may be composed of one or more loops of chain, as shown at 23 in Fig. 4, to increase the cutting action at the free U end of the flexible element. Element I6 may; have only a single weight at the end thereof as shown in Fig. 4, or as shown in Fig. 1 it may have one or more intermediate weights which may take the form of masses strung on or attached to the flexible element or be'short flexible members I8 attached to the element I 6 "at one or more points along its length to increase the cutting action. Such lateral elementsmay be similar one to another as regards length, unit: or total weight, etc., or they may be of 'diiferent lengths, different unit or total weights, etc. Similarlythe lateral elements may be" supported from the main element Id at equal distances or they may have different spacings. The lateral I elements may also be weighted if preferredl or they may take the form of one -or more loops as shown at 23 in Fig. 4. Flexible element I6 when composedof a chain maybe of any suitable construction, preferably being composed of ordinary link members so that replacement or repair-may besimple and inexpensive. However, 7 if preferred, the flexible element may be constructed in any other suitable way, have links of different lengths, construction, etc., or it may be a cable, rope or the like.

share th eq fi ee it in marvel,

4- bunker after a rat hole 28 has formed in the coal 2|. In this figure the flexible element It with its lateral elements I8 is shown as hanging in the rat hole 20"prior to"init iati ngj operation of the motor I3. 'lf-motor- I3 be now started to initiate rotation of element I6 centrifugal force will cause element I6 to bow outwardly intermediate of. its extremities and cut away the coal where the mer ence-11mm the sides of the rat hole; causing the'fdisplaced coal to flow out of th'b unke r by gravity,

Element I6 marten-anew to assume different configurationsl'during rotation by varying the speedlofrotationj and by varying the disposition of theinassesalongfthe element. This is illustrated by the diagrams of Figs. 2 and 3. One configurationbf 'the'flexible element when provided with one weight at the end thereof is indicated ill full line in Fig. 2 at O, A, B, C, the volume ofrevolution swept outby the element being indicated by said full:, line and the symmetrically disposed dotted line corresponding thereto. If the'fspeed of rotation is now increasedthepositions of node Bf and peak A o'fthe configuration'"changes to the pathindicated at O, A, Bf, C". 'Thus'Fig} 2 illustrates that, as the speed of rotation" is progressivelyincreased from zero through certain, successive values, the weight I9 oi' ele'ment' I6 describe's a path from its center position D at thea'xisthrough C, C, etc., the nodal point moving upwardlyjfrom B to B and the maximum amplitude of the loop above the axis increasing from A Xto AX the transverse plane of said maximum amplitude also moving upwardly. Thus selectingthe speed of rotation of the flexible element the configuration of the volume definedl by thedis'placement thereof can be controlled and adapted to the geometry of the par'ticularbunkerfwithwhich itis associ'a tedl" 'Atta'chmentof side elements I8 to saidmain element Ilialso resultsinan increase in the volumethrough 'which the rotating element. is effestive, as it is apparent thattheside elements will move outwardly under, centrifugal force to va rying' degrees', depending'upen thespeed of r0- ta'tionof'th'e element I6, the free ends of'the lateral elements cutting through the coal to breakupits formation. 7

Another mode er rotation of elenyientv I6 is indicat d in Fig.3 in which twocomplete loops are obta ned as compared, to the one complete loop shown in Fig. Here', at relatively low speed theconfigurationof element I6 is' represented' by h f 1 11.? Q R-' S, T, U and. thei'volume cu't outjtherebyis indicated by said full line and the symmetrical" dotted line conforming thereto. On increasing the'speed of rotationa new path is .i SQF D Q. n eeeeie l 1 3. Q3 S, T, Uf and thefvolume of revolution is', cor% respondingly'changed. It willbenoted that the volume swept, bythe "element in Fig. 3' differs in shape from that swept by the element in Fig. 2, and thus by use of the. mode. of rotation indi-' cated in Fig.1; 3 theinvention may, be adapted toibu'nkerv configurations for which the mode of rotation indicated mag. 2 would be unsuitable.

Otherconfigurations and their corresponding volumes of rev olut'on than shown in, Figs. 2

andYS are possible as will be; apparent 'to those skilled "ini' theart and employment thereofin the present invention is contemplated, it being expressly understoodfthat the, configurations Ski) tration my eatrrin:

in FigsQ'Z" and E 3 are, for purposes, of. illii s ferent modes and speeds of rotation suitable to the particular bunker to which the flexible element is applied. The preferred mode of rotation may be stabilized by placing weights or side elements along the main element l6 at selected points where peak amplitudes and nodes are desired.

Whereas proper placement of weights along the length of the element It, as represented by the lateral elements or weights l8, tends to stabilize the operation of the flexible element to effect given configurations and volumes at different speeds of rotation thereof, under some conditions it may be desirable to avoid a stabilized mode of rotation and provide for random motion of the element It. Such may be obtained by placing weights or side elements l8 along the main element H5 at non-uniform spacings or by using weights of unequal value or both. In place of using side elements, weights may be used along the length of the main element It, but suitably proportioned side elements are preferred because they not only operate as weights in determining the location of the nodes and points of maximum amplitude under different speeds of rotation but also increase the cutting action of the device and the volume embraced therein because of their swinging outwardly into cutting contact with the material at the sides of the rat hole depending on the speed of rotation. When unequal weights are desired as above referred to the side elements may be of unequal length or unequal unit or total weights or as previously referred to the side elements may be variously weighted or take the form of one or more loops.

If as a result of the operation of the flexible element as before explained the material should fall as an avalanche and engulf the lower portion of the flexible element preventing rotation thereof, in the absence of an overload clutch or its equivalent as before explained, continued rotation of the element would damage either the element or the motor l3. With an overload clutch, however, the stoppage of the element l6 does not prevent the motor l3 from continuing to drive the shaft I 4 but the output member I! of the clutch [5 will slip or release with respect to the input member thereof.

lVhile in the drawing the main element l6 has been shown as suspended coaxially with the shaft I4 the suspension may be eccentric with respect to the shaft M to introduce other modes of rotation. To increase the efiective range and adaptability of the device the entire unit may be mounted, as heretofore pointed out, so that its position may be adjusted with respect to the bunker. Any suitable provisions for such adjustments may be employed. The eccentricity adjustment may be accomplished by a radially slidable connection between the clutch output member I l and the upper extremity of the chain l6, as shown in. enlarged detail in Fig. 5, and the increase in effective operative range may be accomplished as by making the unit as a whole adjustable laterally as shown in Fig. 1.

While the present invention has been illustrated as breaking loose the material being delivered after a rat hole has formed, it can be used if desired to prevent the formation of a rat hole, and furthermore it may be used in aiding the removal of material from bunkers and the like where unaided gravity discharge normally results in large dead storage volumes.

It will therefore be perceived that the present invention provides a bunker emptying means of wide utility which by reason of its construction and operation can be adapted to a great variety of bunkers and conditions, and by variations in the speed of operation and in the disposition of weights the volume and configuration defined by the rotating flexible element, with or without lateral elements, can be modified to meet a wide variety of exigencies. and strong and readily and inexpensively repaired .in event of breakage. The construction furthermore assures that in the event the material imposes a heavy load on the rotating element the driving motor shall not be injured.

While the embodiments of the invention illustrated on the drawings have been described withconsiderable particularity, it is to be expressly understood that the invention is not limited thereto, as will now be apparent to those skilled in the art. While a flexible element with a weight or loops at the end is preferred, such may be omitted within the broader aspects of the invention to obtain some of the benefits thereof. Through use of the principles hereinabove explained, by suitably locating the weights lengthwise of the element It to predetermine the nodes and planes of maximum displacement the-device can be constructed to meet the requirements of a wide variety of conditions, and by use of suitable side elements, with or without weights thereon, and either singly or in the form of one ormore loops, the total volume defined by the rotating element can be predetermined to meet the requirements of a widevariety of bunkers. Changes may also be made in the details of construction, arrangement and proportion of parts, other provisions than above described may be employed for driving the flexible element, for providing overload slippage or release, for providing lateral adjustment of the flexible element, etc., without departing from the spirit of this invention. Reference is therefore to be had to the appended claims for a definition of said invention.

What is claimed is:

1. In a bunker emptying means, in combination with a bunker having an outlet at the lower portion thereof, a motor mounted adjacent the top of the bunker and having a vertical shaft driven thereby and terminating adjacent the top of the bunker, a freely hanging flexible element extending throughout its entire length downwardly below said shaft from near the top of the bunker to near the outlet thereof approximately at the vertical axis of the bunker, at least one weight disposed intermediate the ends of said flexible element, and connecting means between said shaft and the upper end of said element for rotating said element around a vertical axis to flex said element and generate a geometrical surface of revolution as it rotates.

2. In a bunker emptying means, in combination with a bunker having an outlet at the lower portion thereof, a motor mounted adjacent the top of the bunker and having a vertical shaft driven thereby and terminating adjacent the top of the bunker, a freely hanging flexible element extending throughout its entire length downwardly below said shaft from near the top of the bunker to near the outlet thereof approximately at the vertical axis of the bunker, at least one short flexible element attached to said freely hanging element intermediate the ends thereof,

and connecting means between said shaft and the upper end of said element for rotating said element around a vertical axis to flex said element The construction is simple 

